ΠΕΡΙΓΡΑΜΜΑ ΜΑΘΗΜΑΤΟΣ

This course is divided into two thematic sections. The first deals with the main ways of controlling the growth of unwanted microorganisms (allergens, pathogens) in food, while the second deals with the beneficial effects of beneficial microorganisms in food. Regarding the first unit, the purpose of this is for students to know the main physical and chemical ways in which we can prevent microbial growth and/or kill microorganisms in any food, how each way brings about the desired antimicrobial effect (mode of action) and by what factors this effect is affected (in relation to the nature of the food, the nature of the micro-organisms and the nature of the antimicrobial treatment). Thus, in this section, the processes of cleaning and disinfection (sanitization), the killing of microorganisms through heat treatment, the microbiostatic effects of low temperature (refrigeration, freezing) and low water activity (aw) are analyzed, the process of reducing the pH of a food through the addition of various weak organic acids to limit microbial growth, the preservation of food by packaging it under a modified atmosphere, the addition of various chemical antimicrobial substances (preservatives) to food and finally the microbicidal action of food irradiation. Regarding the second unit, the purpose of this is for students to know the main beneficial actions of microorganisms for food.
Thus, it focuses on the main types of microorganisms used in food fermentations (lactic acid bacteria), on the microbiology of some fermented foods (yoghurt, cheese, fermented cold meats and vegetables) and finally on probiotic microorganisms (Bifidobacterium, Lactobacillus) and the putative positive effects of these in human health (reduction of intestinal disorders, prevention of colon cancer, immune regulation, etc.).
The laboratory exercises aim to better understand some of the key topics covered by the theory of the course.

• Decision making.
• Autonomous work.
• Team work.
• Generating new research ideas.
• Demonstrating social, professional and ethical responsibility and sensitivity to gender issues Exercise criticism and self-criticism.
• Promotion of free, creative and inductive thinking.

Theory

• Control of the entry (access) of microorganisms to food (sanitization process).
• Control of microorganisms through heat treatment.
• Control of microorganisms through low temperature.
• Control of microorganisms through reduced water activity.
• Control of microorganisms through low pH and organic acids.
• Control of microorganisms through modified atmosphere.
• Control of microorganisms through chemical antimicrobial compounds (preservatives).
• Control of microorganisms through irradiation.
• Microorganisms used in food fermentations (fermentative, beneficial).
• Starter cultures and bacteriophages.
• Microbiology of fermented foods (fermented dairy products, cured meats and vegetables).
• Beneficial intestinal bacteria (probiotic microorganisms and effect on human health).

Laboratory

• Effect of water activity (osmotic pressure) on microbial growth.
• Efficacy assessment of chemical antimicrobial agents – Well diffusion method.
• Isolation of lactic acid bacteria from fermented milk products (yoghurts) and study of biochemical properties (catalase and carbohydrate fermentation tests).
• Microbiological examination of water by means of the multiple fermentation method in tubes (most probable number method).
• ONPG and IMViC biochemical tests.

Συγγράμματα

1. Βιβλίο [94700703]: ΜΙΚΡΟΒΙΟΛΟΓΙΑ ΤΡΟΦΙΜΩΝ, ΤΥΜΠΗΣ Δ., ΠΕΤΡΑΚΗΣ Ε., ΚΟΝΤΕΛΕΣ Σ.
2. Βιβλίο [94690299]: ΜΙΚΡΟΒΙΟΛΟΓΙΑ ΤΡΟΦΙΜΩΝ, KARL R. MATTHEWS, KALMIA E. KNIEL, THOMAS J. MONTVILLE.
3. Βιβλίο [86200591]: ΜΙΚΡΟΒΙΟΛΟΓΙΑ ΤΡΟΦΙΜΩΝ, Γεώργιος Μπαλατσούρας.